Hydantoin compounds

ABSTRACT

This invention relates to novel 2-(2,4,5-substituted phenyl) hydantoin compounds, intermediates therefor, synthesis thereof, and the use of said compounds for combatting weeds.

This is a continuation of application Ser. No. 07/808,247, filed Dec.12, 1991, now abandoned.

This invention relates to novel 2-(2,4,5-substituted phenyl) hydantoincompounds, intermediates therefor, synthesis thereof, and the use ofsaid compounds for combatting weeds.

More particularly, one aspect of this invention relates to compounds ofthe formula (I) ##STR1## wherein

R₁ is H, C₁₋₄ alkyl, C₂₋₄ alkenyl or halo;

R₂ is H or halo;

R₃ is OH, oxo, C₂₋₅ alkanoyloxy, C₁₋₄ alkylsulfonyloxy, C₁₋₄ akoxy, C₂₋₄alkylenedioxy or halo;

R₄ is H or halo;

R₅ is halo, cyano or C₁₋₄ alkyl;

R₆ is halo; NO₂ ; NH₂ ; CN; C₂₋₈ alkynyl; C₂₋₈ alkenyloxy, C₂₋₈alkynyloxy, O(C₁₋₄ alkylene)_(k) R₇, or S(C₁₋₄ alkylene)_(k) R₇, each ofwhich is optionally substituted by CN or one or more halo; C₁₋₈ alkyloptionally substituted with one or more groups selected from halo andCN; C₂₋₈ alkenyl optionally substituted by one or more halo; C₂₋₅ alkoxycarbonylC₁₋₄ alkyl, whereby the carbon atom of the alkyl group alpha tothe alkoxycarbonyl group may be substituted with one more C₂₋₅alkoxycarbonyl group or a cyano group; C₂₋₅ alkoxycarbonyloxy; C₂₋₅alkoxycarbonylC₁₋₄ alkoxyC₁₋₄ -alkyl; C₂₋₅ alkoxycarbonylC₂₋₅ alkenyl,whereby the alkenyl group is optionally substituted by halogen; C₁₋₄alkylthioC₁₋₄ alkyl; C₁₋₄ alkylsulfonylC₁₋₄ alkyl; C₁₋₄ alkylsulfonyl;C₁₋₄ alkylsulfonyloxy; C₁₋₄ alkoxyC₁₋₄ alkoxy; OCH(SR₈)COOR₉ ; NR₁₀ R₁₁; COOR₁₂ ; C(O)NR₁₃ R₁₃ '; C(O)R₁₄ ; R.sub. 15 ; CR₁₄ (OC₁₋₂ alkyl)₂ orCR₁₄ (SC₁₋₂ alkyl)₂ whereby the alkyl groups optionally join together toform a ring; CR₁₄ ═NOR₁₃ ; thienylC₁₋₄ alkoxy wherein the thienyl isoptionally halo substituted; or C₁₋₄ alkoxyC₁₋₄ alkoxycarbonyl;

or R₅ and R₆ join together with the phenyl ring to form a bicyclic ringcontaining nine to ten ring atoms, one to three of said ring atomsoptionally being selected from oxygen, nitrogen and sulfur, andoptionally being substituted with one or more groups selected from C₂₋₈alkynyl, halo, oxo, C₁₋₄ alkylene-R₁₆, and C₂₋₈ alkenyl and C₁₋₈ alkylwhich is itself optionally substituted by C₂₋₅ alkoxycarbonyl, C₁₋₄alkoxy or CN;

R₇ is H; C₁₋₄ alkyl, C₂₋₅ alkenyl, C₂₋₅ alkynyl, or C₃₋₈ cycloalkyl,which hydrocarbyl is unsubstituted or substituted by one or more halo orby CN; cyclopentanonyl; phenyl optionally substituted by O-C₁₋₄alkylene-COOR₈ ; C₂₋₅ alkanoyl; C₂₋₅ alkoxycarbonyl wherein the alkoxyis optionally substituted by C₁₋₄ alkylthio; C(O)NR₈ R₈ '; C(═NOR₈)COOR₈'; P(O)(OR₈)OR₈ '; R₁₅ ; C(O)R₁₅ ; cyclopentoxycarbonyl; or phenoxy;

R₈ and R₈ ' independently are C₁₋₄ alkyl;

R₉ is C₁₋₄ alkyl optionally substituted by one or more halo;

R₁₀ is H or C₁₋₄ alkyl;

R₁₁ is H; C₁₋₄ alkyl, optionally substituted by P(O)(OR₈)R₈ '; C₂₋₅alkanoyl; C₂₋₅ alkoxycarbonyl; or C₂₋₅ alkoxycarbonylC₁₋₄ -alkyl;

R₁₂ is H; C₁₋₁₀ alkyl; phenyl; an aromatic 5- or 6-membered ringcomprising 1 to 3 heteroatoms selected from oxygen, sulphur andnitrogen; N═C₂₋₈ alkylidene; or C₁₋₄ alkyl substituted by one or moregroups selected from C₁₋₁₀ alkyl, cycloalkyl, C₂₋₁₀ alkenyl,cycloalkenyl, C₂₋₁₀ alkynyl, NR₁₀ R₁₁, C₁₋₄ alkylthio, CN, phenyl, anaromatic 5- or 6-membered ring comprising 1 to 3 heteroatoms selectedfrom oxygen, sulphur and nitrogen, C₂₋₅ alkanoyl, halo, C₁₋₄ alkoxy,tri(C₁₋₄ alkyl)silyloxy, tri(C₁₋₄ alkyl)silyl, C₂₋₄ alkoxycarbonyl,P(O)(OR₈)OR₈ ', C₂₋₅ alkanoyloxy, and di(C₁₋₄ alkyl)aminocarbonyloxy inwhich both alkyl groups may be tied together to form a saturated 5 to 6membered heteroring optionally containing one further heteroatomselected from O, S and N, and in which any further N-heteroatom presentmay, depending on the hydrogenation degree of the heteroring, bear ahydrogen or a C₁₋₄ alkyl group;

R₁₃ is H or C₁₋₄ alkyl; and

R₁₃ ' is H, C₁₋₄ alkyl, C₁₋₄ alkoxy, phenyl, CHO, C₂₋₅ alkanoyl, C₁₋₄alkylsulfonyl, C₂₋₅ alkoxycarbonylC₁₋₄ alkyl or C₂₋₅ alkoxycarbonylC₁₋₄alkoxy; or

R₁₃ and R₁₃ ' together form a 5 to 6 membered heteroring optionallycontaining one or two further heteroatoms selected from O, S and N,whereby, depending on the hydrogenation degree of the heteroring, anyfurther N-heteroatom may bear hydrogen or be substituted by C₁₋₄ alkyl;

R₁₄ is H or C₁₋₄ alkyl;

R₁₅ is a heterocyclic ring having 5 or 6 ring atoms, one to three ofsaid ring atom being selected from oxygen, sulfur and nitrogen, whichring is optionally substituted with one or more groups selected fromC₁₋₄ alkyl and C₂₋₅ alkoxycarbonyl;

R₁₆ is tetrahydropyranyl, 5,6-dihydro-2H-thiinyl, pyridyl, pyrazinyl,oxazolyl, or oxadiazolyl all of which are optionally substituted withC₁₋₄ alkyl;

X₁ and X₂ are independently O or S;

k is 0 or 1; and

n and m are independently 1 or 2;

with the proviso that when R₁ and R₂ are H and m is 1, R₃ cannot be C₁₋₄alkoxy.

Any alkyl group in the compound of formula (I) may be branched orstraight chain and preferably has one to four carbon atoms.

Any alkenyl or alkynyl group may be either branched or straight chainand preferably has two to five carbon atoms.

Halo as used herein, refers to Cl, F, Br or I.

Any cycloalkenyl group preferably has five to six carbon ring atoms.

Any cycloalkyl group preferably has three to five carbon ring atoms.

When R₃, R₆, R₇, R₉ or R₁₂ is substituted by halogen, it is preferablychlorine or fluorine, more preferably fluorine.

Where R₅ and R₆ join together with the phenyl ring to form a bicyclicring, it is preferably an indanone; a benzazinone, particularly aquinolinone; a benzoxazinone; a benzodiazinone, particularlydihydroquinoxalinone; a benzothiazinone; a benzodioxane; a benzopyrane;a benzopyrone, particularly coumarin; a benzazole, particularly anindole, an indolone, an indazole, a benzotriazole, an isatine or abenzimidazolone; a benzoxazolone; a benzothiazolone; a benzofurane; or abenzdioxolane.

n is preferably 2. Where n is 2, preferably at least one R₃ is in the7-position.

m is preferably 1.

R₆ is preferably C₁₋₄ alkoxy, C₂₋₅ alkenyloxy, C₂₋₅ alkynyloxy, C₂₋₅haloalkenyl, C₂₋₅ alkynyl or COOR₁₂, in which R₁₂ is as defined above.Typical examples of preferred R₆ significances include isopropoxy,methoxy, O-CH(CH₃)-C≡CH, C≡CH, COOCH₃, COOCH(CH₃)₂, COOC(CH₃)₃ andCOOCH(CH₂ F)₂. R₆ is more preferably C₁₋₄ alkoxy.

R₁ is preferably hydrogen or halo, more preferably hydrogen.

R₂ is preferably hydrogen.

One of R₃ is preferably halo, more preferable fluoro or chloroparticularly fluoro.

R₄ is preferably F.

R₅ is preferably C₁₋₄ alkyl, halo or CN, particularly Cl.

A particularly preferred subgroup of compounds of the formula (I) arethose in which X₂ is oxo, R₁ is H or halo, R₂ is H, R₃ is OH, halo oroxo, R₄ is F, R₅ is Cl, CN or Br, and R₆ is C₁₋₄ alkoxy, C₂₋₅ alkynyl,C₂₋₅ alkoxycarbonyloxy, C₂₋₅ alkoxycarbonyl, C₂₋₅ alkoxycarbonylC₁₋₄alkoxy, phenoxyC₁₋₄ alkoxy, C₁₋₄ alkoxyC₁₋₄ alkoxy or C₁₋₄ alkoxyC₁₋₄alkoxycarbonyl.

Compounds of the formula (I) are useful because they demonstrateherbicidal activity.

Compounds of the formula (I) can be obtained through the condensationreaction between the amide and the group R₁₇ of the compound of formula(II) ##STR2## wherein R₁₋₆, X₁, n and m are as defined above;

R₁₇ is C(X₂)OH; C(X₂)OW; COSW; COON═CWW'; CONHSO₂ W; CONHOCH₂ COOW;COOCHO₂ COW; COOCHWOCOW'; or CONHOCH₂ COOH; and

W and W' are independently C₁₋₈ alkyl, C₂₋₈ alkenyl, C₂₋₈ alkynyl, orphenyl, each of which is optionally substituted by CN, C₁₋₄ alkoxy orone or more halo.

This condensation reaction is carried out under conditions that aretypical for preparing hydantoin compounds. The reaction is facilitatedby the presence of an acid or an alkaline agent.

In cases where n is 1, the condensation reaction is preferably carriedout under acidic conditions. Accordingly, the reaction may be carriedout in an inert medium such as dioxane in the presence of an acid suchas HCl. Suitable temperatures range from about room to refluxtemperature, the preferred temperature being reflux. The desiredend-product may be obtained from solution by known techniques such asdistillation, crystallization and chromatographic methods.

In cases where n is 2, the condensation reaction may be carried outunder acidic or alkaline conditions. Accordingly, the reaction may becarried out in an inert medium such as toluene in the presence of analkaline agent such as triethylamine. Suitable temperatures range fromabout room to 60° C., preferably about 50° C. The resulting product isisolated and purified in accordance with known processes such asextraction and crystallization.

Compounds of the formula (II) are useful not only as intermediates inthe production of compounds of the formula (I), but also because theythemselves demonstrate herbicidal activity. Preferred groups n, m, andR₁₋₆ are as previously mentioned. Where W and/or W' is optionallysubstituted C₁₋₈ alkyl it has preferably 1-4 carbon atoms. Where Wand/or W' is optionally substituted C₂₋₈ alkenyl or C₂₋₈ alkynyl it haspreferably 2 to 5 carbon atoms. R₁₇ is preferably COOH or COOC₁₋₄ alkyl.

Compounds of the formula (II) may be prepared by reacting a compound ofthe formula (III) ##STR3## wherein R₁₋₃, R₁₇, n and m are previouslydefined with the desired substituted phenyl isocyanate orisothiocyanate. This reaction may be carried out in an inert medium suchas toluene, preferably at ambient temperature. The resulting compound offormula (II) can be recovered from solution by standard separationtechniques, e.g. suction filtration and chromatography.

The substituted phenyl isocyanates or isothiocyanates to be employed inthe process for the preparation of the compounds of formula II areknown. Compounds of the formula (III) are either known or can beprepared from known compounds according to known procedures.

Certain compounds of the formulae (I) and (II) wherein R₃ is other thanOH are conveniently prepared by first preparing the correspondingcompound wherein R₃ =OH followed by the appropriate exchange of R₃substituents, or, in the case of R₃ =oxo, oxidation.

Thus, e.g., compounds of formulae (I) or (II) in which R₃ =fluoro, oxoor acetoxy can be prepared by treating compounds of formulae (I) or (II)in which R₃ is OH with e.g. SF₄ or diethylaminosulphurtrifluoride(DAST), an oxidation agent such as dimethylsulfoxide/diphosgene orpyridinium chlorochromate, or acetic anhydride, respectively.

Further, compounds in which m=2 and R₃ is F with both F attached to thesame carbon atom can be prepared by treating the corresponding compoundin which R₃ =oxo with e.g. DAST or SF₄.

Regio-isomers of the formula I wherein n is 2, R₁ and R₂ are H and(R₃)_(m) is 6-OH, 7-F or 6-F, 7-OH and wherein R₄₋₆, X₁ and X₂ are aspreviously defined can be prepared by treating a compound of the formulaIV ##STR4## wherein R₄₋₆, X₁ and X₂ are as previously defined with e.g.triethylamine-tris-hydrofluoride. Compounds of the formula IV are eitherknown or obtainable from known, analogous starting materials using knownprocedures.

The compounds of formulae (I) and (II) are effective in controlling thegrowth of plants. By plants it is meant germinating seeds, mergingseedlings and established vegetation including underground portions. Inparticular, the compounds are useful as herbicides as indicated bycausing damage to both monocotyledoneous and dicotyledoneous plants invarious standard evaluations for determining such effects. Theherbicidal effects are exhibited both pre- and post-emergence theplants. Such herbicidal effects indicate that the compounds of formulae(I) and (II) are particularly of interest in combatting weeds (unwantedplants).

The compounds of the formulae (I) and (II) are indicated mainly to bestronger acting against dicotyledoneous plants than monocotyledoneousplants. Relatively less toxicity towards crops than towards weeds isfurther indicated. Hence, the compounds are of particular interest asselective herbicides to combat weeds in a crop locus, particularly aslocus of a crop such as, for example, sugarbeet, sunflower, cottonsoybean, corn and wheat.

The present invention therefore also provides a method of combattingweeds in a locus which comprises applying to the weeds or their locus aherbicidally effective amount of a compound of the invention. Whenselective action is desired in crop locus, the amount applied will besufficient to combat weeds without substantially damaging the crop.

For general herbicidal as well as selective herbicidal use of thecompounds of the invention, the particular amounts to be applied willvary depending upon recognized factors such as the compound employed,the plants primarily in the locus, the timing, mode and formulation inapplication, the various conditions of treatment such as soil andweather and the like. However, in general, satisfactory results in weedcontrol are usually obtained upon application of the compounds of theinvention at a rate in the range of from 0.001 to 2 kg/hectare, moreusually 0.01 to 1 kg/hectare, and preferably 0.01 to 0.25 kg/hectare,the application being repeated as necessary. When used in crops, theapplication usually will not exceed about 1 kg/hectare, and is usuallyin the range of 0.01 to 0.5 kg/hectare.

For practical use as herbicides, the compounds of formulae (I) and (II)may be and are preferably employed in herbicidal compositions comprisinga herbicidal effective amount of the compound and an inert carrier whichis agriculturally acceptable in the sense of not, by reason of itspresence, poisoning the agricultural environment including the immediatesoil of application or any crops present therein or otherwise beingunsafe for application. Such compositions of formulations may contain0.01% to 99% by weight of active ingredient, from 0 to 20% by weight ofagriculturally acceptable surfactants and 1 to 99.99% by weight of theinert carrier. Higher ratios of surfactant to active ingredient aresometimes desirable and are achieved by incorporation into theformulation or by tank mixing. Application forms of compositiontypically contain between 0.01 and 25% by weight of active ingredient,but lower or higher levels of active ingredient can, of course, bepresent depending on the intended use and the physical properties of thecompound. Concentrate forms of composition intended to be diluted beforeuse generally contain between 2 and 90%, preferably between 10 and 80%by weight of active ingredient.

Useful compositions or formulations of the compounds of the inventioninclude dusts, granules, pellets, suspension concentrates, wettablepowders, emulsifiable concentrates and the like. They are obtained byconventional manner, e.g. by mixing the compounds of the invention withthe inert carrier. More specifically, liquid compositions are obtainedby mixing the ingredients, fine solid compositions by blending and,usually grinding, suspensions by wet milling and granules and pellets byimpregnating or coating (preformed) granular carriers with the activeingredient or by agglomeration techniques.

For example, dusts can be prepared by grinding and blending the activecompound with a solid inert carrier such as talc, clay, silica and thelike. Granular formulations can be prepared by impregnating thecompound, usually dissolved in a suitable solvent, onto and intogranulated carriers such as the attapulgites or the vermiculites,usually of a particle size range of from about 0.3 to 1.5 mm. Wettablepowders, which can be dispersed in water or oil to any desiredconcentration of the active compound, can be prepared by incorporatingwetting agents into concentrated dust compositions.

Alternatively, the compounds of the invention may be used inmicro-encapsulated form.

Agriculturally acceptable additives may be employed in the herbicidalcompositions to improve the performance of the active ingredient and toreduce foaming, caking and corrosion.

Surfactant as used herein means agriculturally acceptable material whichimparts emulsifiability, spreading, wetting, dispersiblity or othersurface-modifying properties properties. Examples of surfactants aresodium lignin sulphonate and lauryl sulphate.

Carriers as used herein mean a liquid or solid material used to dilute aconcentrated material to a usable or desirable strength. For dusts orgranules it can be e.g. talc, kaolin or diatomaeous earth, for liquidconcentrate forms, a hydrocarbon such as xylene or an alcohol such asisopropanol; and for liquid application forms, e.g. water or diesel oil.

The compositions of this application can also comprise other compoundshaving biological activity, e.g. compounds having similar orcomplementary herbicidal ativity or compounds having antidotal,fungicidal or insecticidal activity.

Typical herbicidal composition, according to this invention, areillustrated by the following Examples A, B and C in which the quantitiesare in parts by weight.

EXAMPLE A

Preparation of a Dust

10 Parts of a compound of formulae (I) or (II) and 90 parts of powderedtalc are mixed in a mechanical grinder-blender and are ground until ahomogeneous, free-flowing dust of the desired particle size is obtained.This dust is suitable for direct application to the site of the weedinfestation.

EXAMPLE B

Preparation of Wettable Powder

25 Parts of a compound of formulae (I) or (II) are mixed and milled with25 parts of synthetic fine silica, 2 parts of sodium lauryl sulphate, 3parts of sodium ligninsulphonate and 45 parts of finely divided kaolinuntil the mean particle size is about 5 micron. The resulting wettablepowder is diluted with water before use to a spray liquor with thedesired concentration.

EXAMPLE C

Preparation of Emulsifiable Concentrate (EC)

13 Parts of a compound of formulae (I) or (II) are mixed in a beakerwith 7 parts of Toximul 360A (a mixture of anionic and non-ionicsurfactants containing largely non-ionic surfctants), 24 parts ofdimethylformamide and 56 parts of Tenneco 500-100 (predominantly amixture of alkylated aromatics such as xylene and ethylbenzene) untilsolution is effected. The resulting EC is diluted with water for use.

FINAL COMPOUNDS

Unless otherwise indicated, temperatures herein stated are in Celsius.

EXAMPLE 12-[4-chloro-2-fluoro-5(isopropoxy)-phenyl]-7-hydroxy-tetrahydroimidazo{1,5a]-pyridine1,3 (2H,5H)-dione.

545 mg (2.38 mmole) of solid, finely powdered4-chloro-2-fluoro-5-isopropoxyphenyl isocyanate are added with stirringto a solution of 380 mg (2.38 mmole) of 4-hydroxy-2-piperidinecarboxylic acid methyl ester in 10 ml of anhydrous toluene.

The reaction solution is stirred at room temperature for a period of 3hours and is then filtered by suction. The organic solvent isevaporated. The crude product is chromatographed on a silica gel columnwith hexane:ethyl acetate (4:1).

The title compound is obtained as a colorless powder with a m.p. of156°-158° C. (compound 1.1, Table A).

EXAMPLE 22-[4-chloro-2-fluoro-5(isopropoxy)-phenyl]-7-fluoro-tetrahydroimidazo[1,5a]-pyridine1,3 (2H,5H)-dione.

To a stirred solution of2-[4-chloro-2-fluoro-5-(isopropoxy)phenyl]-7-hydroxy-tetrahydro-imidazo[1,5a]-pyridine1,3 (2H,5H)-dione (1 g, 2,8 mmole) in 20 ml anhydrous methylene chlorideat -78° C. is added in one portion 1,36 ml ofdiethylaminosulphurtrifluoride (DAST). The reaction mixture is broughtto room-temperature and stirred for 12 hours.

The reaction mixture is evaporated and purified on a silica gel columnwith hexane:ethyl acetate (1:1). The desired product is obtained as aliquid (compound 1.2, Table A), Rf=0.42 (on silica gel with hexane-ethylacetate 1:1).

EXAMPLE 32-[4-chloro-2-fluoro-5(isopropoxy)-phenyl]-tetrahydro-imidazo[1,5a]-pyridine-1,3-(2H,5H)-7-trione.

To a stirred solution of2-[4-chloro-2-fluoro-5(isopropoxy)phenyl]-7-hydroxy-tetrahydro-imidazo[1,5a]-pyridine1,3 (2H,5H)-dione (200 mg, 0.56 mmole) in 10 ml anhydrous methylenechloride at room temperature are added 270 mg (1,26 mmole) of pyridiniumchlorochromate. Stirring is continued for 12 hours at room temperature.The reaction mixture is filtered over silica gel and then purified on asilica gel column.

Elution with ethyl acetate:hexane affords the title compound as acolourless powder with a m.p. of 63°-65° C. (compound 1.3, Table A).

EXAMPLE 42-[4-chloro-2-fluoro-5(isopropoxy)-phenyl]-7,7-difluoro-tetrahydroimidazo[1,5a]-pyridine-1,3-(2H,5H)-dione.

450 mg (2,8 mmole) of diethylaminosulphurtrifluride are added to 500 mg(1,4 mmole) of2-[4-chloro-2-fluoro-5(isopropoxy)phenyl]-tetrahydro-imidazo[1,5a]-pyridine-1,3,7-trioneand stirred at room temperature for 2 hours. The reaction mixture isthen diluted with methylene chloride and evaporated to dryness. Theresidue is chromatographed on a silica gel column with hexane:ethylacetate (7:3) as eluent.

The title compound is then isolated as a colourless powder with m.p. of107°-109° C. (compound 1.4, Table A).

EXAMPLE 5Tetrahydro-2-[4-chloro-2-fluoro-5-isopropoxy)phenyl]-6-hydroxy-1-H-pyrrolo[1,2-c]imidazole-1,3(2H)-dione

A solution of 1.4 g (3.74 m moles) of1-[[4-chloro-2-fluoro-5-isopropoxyphenyl)amino]-4-hydroxypyrrolidine-2-carboxylic acid methyl ester in 15 ml of dioxane and 20 mlof 2N hydrochloric acid is refluxed for 1.5 hours and is then evaporatedin vacuo (60°/20 torr).

The residue is taken up with 100 ml of methylene chloride and filtered.The residual syrup left on rotevaporation of the dried (Na₂ SO₄)filtrate is chromatographed on a silica gel column. Elution with ethylacetate furnishes the title compound as a viscous oil having a R_(f) :0.57 (on silica gel with ethyl acetate) (compound 1.5, Table A).

Following the procedure of Example 5, compounds 1.6-1.53 of Table A,below are synthesized.

                                      TABLE A                                     __________________________________________________________________________    Compounds of the formula (I) in which X.sub.2 is O, R.sub.2 is H and          R.sub.4 is F.                                                                 __________________________________________________________________________    Compound                                  m.p. or Rf                          No.   n    X.sub.1                                                                          R.sub.1                                                                             R.sub.6 (R.sub.3).sub.m                                                                         R.sub.5                                                                           on silica gel                       __________________________________________________________________________    1.1   2    O  H     isopropoxy                                                                            7-OH      Cl  156°-158°             1.2   2    O  H     isopropoxy                                                                            7-F.sup.1 Cl  0.42                                                                          (hexane:ethyl)                                                                acetate 1:1)                        1.3   2    O  H     isopropoxy                                                                            7-oxo     Cl  63-65°                       1.4   2    O  H     isopropoxy                                                                            7,7-di-F  Cl  107-109°                     1.5   1    O  H     isopropoxy                                                                            6-OH(6R,7aS)                                                                            Cl  0.57 (ethyl                                                                   acetate)                            1.6   1    O  H     isopropoxy                                                                            7-OH.sup.2                                                                              Cl  175-176° C.                  1.7   2    S  H     CH.sub.2 C.tbd.CH                                                                     8-oxo     Cl  199-201°                     1.8   2    O  H     isopropoxy                                                                            B-OH.sup.3                                                                              Cl  124-125°                     1.9   1    O  H     isopropoxy                                                                            6-F       Cl  90-92° C.; 0,13                                                        (hexane:ethyl-                                                                acetate 1:1)                        1.10  1    O  H     isopropoxy                                                                            7-F.sup.4 Cl  0.25                                                                          (hexane:ethyl-                                                                acetate 1:2)                        __________________________________________________________________________    Compound                                                                      No.     n X,   R,    (R.sub.3).sub.m                                                                     R5  R6       m.p. or Rf or SiO.sub.2               __________________________________________________________________________    1.11    2 O    H                                                              7OH     CN                                                                              isopropoxy                                                                         206°-208°                                        1.12    2 O    H                                                              7F      CN                                                                              isopropoxy                                                                         147°-149°                                        1.13    2 O    H                                                              7OH     Br                                                                              isopropoxy                                                                         150°-152°                                        1.14    2 O    H                                                              7F      Br                                                                              isopropoxy                                                                         0,32 (Hexane:ethyl-                                                                                    acetate 1:1)                          1.15    2 O    H                                                              7OH     Cl                                                                              methoxy                                                                            189°-191°                                        1.16    2 O    H                                                              7F      Cl                                                                              methoxy                                                                            0,18 (hexane:ethyl-                                                                                    acetate 1:1)                          1.17    2 O    H                                                              7OH     Cl                                                                              methoxy-                                                                           0,44 (ethylacetate 1:1)                                                                       carbonyloxy                                    1.18    2 O    H                                                              7F      Cl                                                                              methoxy-                                                                           0,23 (hexane:ethyl-                                                                           carbonyloxy                                                                            acetate 1:1)                          1.19    2 O    H                                                              7OH     Cl                                                                              hydroxy                                                                            195°-198°                                        1.20    2 O    6-Iodo                                                         7OH     Cl                                                                              isopropoxy                                                                         56°-58°  C.                                                                              0,27 (hexane:ethyl-                                                           acetate 1:1)                          1.21    2 O    6-bromo                                                        7Br     Cl                                                                              isopropoxy                                                                         0,50 (hexane:ethyl-                                                                                    acetate 2:1)                          1.22    2 O    H     6-OH  Cl  isopropoxy                                                                             0,15 (hexane:ethyl-                                                           acetate 4:6                           __________________________________________________________________________    Compound                                                                      No.   n     X.sub.1                                                                         R.sub.1                                                                             R.sub.3                                                                             R.sub.5                                                                             R.sub.6 m.p. or Rf or SiO.sub.2               __________________________________________________________________________    1.23  2     O H     6-F   Cl    isopropoxy                                                                            0,41 (hexane: ethyl-                                                          acetate 4:6)                          1.24  2     O H     6-oxo Cl    isopropoxy                                                                            0,20 (hexane:ethyl-                                                           acetate 4:6)                          1.25  2     O H     6,6-diF                                                                             Cl    isopropoxy                                                                            0,30 (hexane:ethyl-                                                           acetate 4:6                           __________________________________________________________________________    Compd.                                                                        No.  n X.sub.1                                                                         R.sub.1                                                                           R.sub.6           (R.sub.3).sub.m                                                                    R.sub.5                                                                         m.p. or Rf on silical                   __________________________________________________________________________                                          gel                                     1.26 2 O H   isopropoxy        7-OH.sup.1                                                                         Cl                                                                              0,32 (ethyl acetate)                    1.27 2 O H   isopropoxy        7-F.sup.3                                                                          Cl                                                                              0,30 (hexane:ethyl acetate 1;1)         1.28 2 O H   methoxy           7-F.sup.3                                                                          Cl                                                                              0,18 (hexane:ethyl acetate 1:1)         1.29 2 O H   --O--CH(CH.sub.3)--CH.tbd.CH                                                                    7-OH Cl                                                                              0,30 (ethyl acetate)                    1.30 2 O H   --O--CH(CH.sub.3)--CH.tbd.CH                                                                    7-F  cl                                                                              166-168°                         1-31 2 O H   methoxy           7-oxo                                                                              Cl                                                                              0,24 (hexane:ethyl acetate 3:7)         1.32 2 O H   methoxy           7,7-di-F                                                                           Cl                                                                              0,17 (hexane: ethyl acetate 1:1)        1.33 2 O H   --C(O)--OCH(CH.sub.3).sub.2                                                                     7-OH cl                                                                              169-171°                         1.34 2 O H   --C(O)--OCH(CH.sub.3).sub.2                                                                     7-F  Cl                                                                              0,40 (hexane:ethyl acetate 1:1)         1.35 2 O H   --C(O)--OCH(CH.sub.3).sub.2                                                                     7-oxo                                                                              el                                                                              0,40 (hexane:ethyl acetate 3:7)         1.36 2 O H   --C(O)--OCH(CH.sub.3).sub.2                                                                     7,7-di-F                                                                           Cl                                                                              0,33 (hexane:ethyl acetate 7:3)         1.37 2 O H   --O--CH(CH.sub.3).sub.--C(O)OCH.sub.3                                                           7-OH.sup.3                                                                         Cl                                                                              0,33 (ethyl acetate acetone 9:1)        1.41 2 O H   --O--CH(CH.sub.3).sub.--C(O)OCH.sub.3                                                           7-OH.sup.1                                                                         Cl                                                                              0,26 (ethyl acetate: acetone 9:1)       1.39 2 O H   --O--CH(CH.sub.3).sub.--C(O)OCH.sub.3                                                           7-F  Cl                                                                              0,25 (ethyl acetate; hexane 1:1)        1.40 2 O 6-Iodo                                                                            isopropoxy        7-F  Cl                                                                              0,41 (hexane; ethyl acetate 1:1)        1.41 2 O H   --O-(CH.sub.2)--O--C.sub.6 H.sub.5                                                              7-OH Cl                                                                              0,30 (ethyl acetate)                    1.42 2 O H   --O-(CH.sub.2).sub.2 --O--C.sub.6 H.sub.5                                                       7-F.sup.3                                                                          Cl                                                                              0,24 (hexane:ethyl acetate 1:1)         1.43 2 O H   --O-(CH.sub.2).sub.2 --O--C.sub.6 H.sub.5                                                       7-F.sup.1                                                                          Cl                                                                              0,28 (hexane:ethyl acetate 1.1)         1.44 2 O H   --C(O)O--CH(CH.sub.3)--CH.sub.2 --OCH.sub.3                                                     7-OH Cl                                                                              0,26 (hexane:ethyl acetate 1:1)         1.45 2 O H   --C(O)O--CH(CH.sub.3)--CH.sub.2 --OCH.sub.3                                                     7-OH.sup.3                                                                         Cl                                                                              0,20 (hexane:ethyl acetate 1:1)         1.46 2 O H   --C(O)O--CH(CH.sub.3)--CH.sub.2 --OCH.sub.3                                                     7-F.sup.3                                                                          Cl                                                                              0,16 (hexane:ethyl acetate 1:1)         1.47 2 O H   --C(O)O--CH(CH.sub.3)--CH.sub.2 --OCH.sub.3                                                     7-F.sup.1                                                                          Cl                                                                              0,24 (hexane:ethyl acetate 1:1)         1.48 2 O H   5--Cl-thien-2-yl-methoxy                                                                        7,7-diF                                                                            Cl                                        1.49 2 O H   5--Cl-thien-2-yl-methoxy                                                                        7-F  Cl                                        1.50 2 O H   ethoxymethoxy     7,7-di-F                                                                           Cl                                        1.51 2 O H   ethoxymethoxy     7-F  Cl                                        1.52 2 O H   --C(O)O--CH(CH.sub.3).sub.3                                                                     7-OH Cl                                                                              154-155°                         1.53 2 O B   --C(O)O--CH(CH.sub.3).sub.3                                                                     7-F  Cl                                                                              0.43 (hexane:diethylether               __________________________________________________________________________                                          1:1)                                     .sup.1 trans with respect to the 8a position                                  .sup.2 cis with respect to the 7a position                                    .sup.3 cis with respect to the 8a position                                    .sup.4 trans with respect to the 7a position                             

REGIO-ISOMERS EXAMPLE 62-Chloro-4-fluoro-5-(hexahydro-1,3-dioxo-imidazo-[1,5a]-7-fluoro-6-hydroxy-pyridin-2(3H)-yl-benzoicacid-1-methyl-ethyl ester and2-Chloro-4-fluoro-5-(hexahydro-1,3-dioxo-imidazo-[1,5a]-6-fluoro-7-hydroxy-pyridin-2(3H)-yl-benzoicacid-1-methyl ethyl ester (compounds of the formula Ia and Ib wherein X₁and X₂ are oxygen, R₄ is F, R₅ is Cl and R₆ is isopropoxycarbonyl)

The heterogenous mixture of 2.7 g (0.007 mol) of2-chloro-4-fluoro-5-(hexahydro-1,3-dioxo-imidazo-[1,5a]-6,7-epoxypyridin-2(3H)-yl)-benzoicacid-1-methylethyl ester and 1.2 ml (0.0074 mol) oftriethylamine-tris-hydrofluoride is stirred, under a nitrogenatmosphere, 16 hours at 110°.

The dark brown reaction mixture is then cooled to ambient, dissolved inmethylene chloride (200 ml), washed with 10% NaHCO₃ solution (100 ml),two 100 ml portions of water, dried (Na₂ SO₄) and evaporated in vacuo.

The resulting crude mixture of the two title compounds is separated bychromatography with hexane-ethyl acetate as the mobile phase: firsteluted (hexane-ethyl acetate 3:2) is the2-chloro-4-fluoro-5-(hexa-hydro-1,3-dioxoimidazo-[1,5a]-7-fluoro-6-hydroxy-pyridin-2(3H)-yl) benzoic acid-1-methylethyl ester; R_(f) =0.38 with ethylacetate hexane 2:1 on silica gel.

Continued elution of the silica gel column (hexane ethylacetate 1:2)affords the regio-isomeric compound, having a m.p. of 134°.

INTERMEDIATES EXAMPLE 71[[(4-chloro-2-fluoro-5-isopropoxyphenyl)amino]carbonyl]-(2R)-4-oxopyrrolidine-2-carboxylicacid methyl ester

To the cooled (-65°) solution of 1,15 g (0,0058 moles) oftrichloromethyl chloroformate in 30 ml of dry CH₂ Cl₂ are added dropwisewith stirring 1,65 g (0,021 moles) of dimethyl sulfoxide.

After the addition is complete, the reaction mixture is stirred for afurther 5 minutes at -70° and then treated--at the sametemperature--with the solution of 2,03 g (0,054 moles) of1[[(4-chloro-2-fluoro-5-isopropoxyphenyl)amino]carbonyl]-cis-4-hydroxy-D-prolinemethyl ester in 50 ml of dry CH₂ Cl₂. After all the proline ester hasbeen added, the reaction mixture is kept at -65° for 15 minutes and isthen treated with 3,6 ml (0,026 moles) of triethylamine.

Then the solid CO₂ /acetone bath is removed the reaction mixture allowedto warm to 17° (50 min) and treated with 75 ml of water. The organiclayer is separated, washed with two 120 ml portions of water and dried(Na₂ SO₄).

The dark brown syrup left on rotevaporation of the methylene chloride ischromatographed on a silica gel column.

Elution with diethyl ether--hexane (1:1) affords the title compound as ayellowish viscous liquid, R_(f) =0,35 (on silica gel with diethyl ether)(compound 2.1, Table B).

EXAMPLE 81[[(4-chloro-2-fluoro-5-isopropoxyphenyl)amino]carbonyl]-(2R)-4-cis-acetoxypyrrolidine-2-carboxylicacid methyl ester

3,75 g (0,01 mol) of1[[(4-chloro-2-fluoro-5-isopropoxyphenyl)amino]carbonyl]-cis-4-hydroxy-D-prolinemethyl ester are dissolved in the mixture of 5 ml of acetic anhydrideand 5 ml of pyridine.

Upon standing for 20 hours at room temperature, the reaction solution isevaporated in vacuo (60°/20 torr). The residue is taken up with CH₂ Cl₂and washed successively with 50 ml of 5% H₂ SO₄, 50 ml of water, 30 mlof saturated NaHCO₃ solution and again with water (75 ml). The residualviscous oil left on rotevaporation of the dried (Na₂ SO₄) methylenechloride, solidifies completely on chilling overnight at -20°: m.p. 92°(triturated with diethylether-hexane (1:9)) (compound 2.2, Table B).

EXAMPLE 9 1[[(4-chloro-2-fluoro-5-isopropoxy)phenyl]aminocarbonyl]-(2S)-4-trans-hydroxy-pyrrolidine-2-carboxylic acidmethyl ester.

6.91 g (30.12 mmole) of solid finely powdered4-chloro-2-fluoro-5-isopropoxyphenyl isocyanate are added in singleportions with stirring to a solution of 4.37 g (30.10 mmol) oftrans-4-hydroxy-L-proline methyl ester in 20 ml of anhydrous toluenesolution.

The reaction solution is stirred at room temperature for a period of 12hours and is then filtered by suction. The organic solvent isevaporated. The crude product is crystallised from ethyl acetate/hexaneas colourless crystals with a m.p. of 136°-138° C. (Compound 2,3, TableB).

EXAMPLE 10 1-[[(4-chloro-2-fluoro-5-isopropoxy)phenyl]aminocarbonyl]-(2S)-4-cis-fluoro pyrrolidine-2-carboxylic acidmethyl ester

To a stirred solution of 1,27 ml (10,4 m mole) ofdiethylaminosulphurtrifluoride (DAST) in 20 ml anhydrous methylenechloride at -78° C. is added a chilled solution of 1 g (2,6 m mole) of1[[(4-chloro-2-fluoro-5-isopropoxy)phenyl]aminocarbonyl]-(2S)-4-trans-hydroxy-pyrrolidine-2-carboxylicacid methyl ester. The reaction mixture is stirred further for two hoursat -78° C. and then brought to room-temperature and stirred further for12 hours at this temperature. The reaction mixture is evaporated andpurified on a silica gel column with hexane: ethyl acetate (3:1). Thedesired product is obtained as a liquid having R_(f) =0.13 (hexane:ethylacetate 3:1) (Compound 2.4, Table B).

EXAMPLE 111[[4-chloro-2-fluoro-5-isopropoxyphenyl)amino]carbonyl]-(2R)-4-cis-hydroxypyrrolidine-2-carboxylicacid methyl ester.

To a stirred solution of 4,2 g (0,029 moles) of cis-4-hydroxy-D-prolinemethyl ester in 50 ml of dry toluene are added dropwise without cooling6,7 g (0,029 moles) of 4-chloro-2-fluoro-5-isopropoxyphenyl isocyanate,dissolved in 250 ml of dry toluene.

After the exothermic reaction (28°) has subsided, the reaction mixtureis stirred 4 hours longer at ambient temperature and is then taken todryness.

The residue is chromatographed on a silica gel column.

Elution with ethyl acetate affords the title compound as a yellowishsyrup (R_(f) =0,33 on silica gel with ethyl acetate) which exhibitssatisfactory spectral properties (Compound 2.5, Table B).

Following the procedure for Compound 2.3, Compounds 2.5-2.14 aresynthesized.

                                      TABLE B                                     __________________________________________________________________________    Compounds of the formula (II) in which R.sub.1 and R.sub.2 are H, R.sub.4     is F and                                                                      R.sub.5 is Cl.                                                                Comp.                          m.p. or R.sub.f on                             No. n X.sub.1                                                                         R.sub.6                                                                              (R.sub.3).sub.m                                                                         R.sub.17                                                                            silica                                         __________________________________________________________________________    2.1 1 O isopropoxy                                                                           4-oxo     COOCH.sub.3                                                                         0.35 (diethyl                                                                 ether)                                         2.2 1 O isopropoxy                                                                           4-acetoxy COOCH.sub.3                                                                         92°                                     2.3 1 O isopropoxy                                                                           4-OH(4trans/2S)*                                                                        COOCH.sub.3                                                                         136-141°                                2.4 1 O isopropoxy                                                                           4-F(4cis/2S)*                                                                           COOCH.sub.3                                                                         0.13                                                                          (hexane:ethyl                                                                 acetate 3:1)                                   2.5 1 O isopropoxy                                                                           4-OH(4cis/2R)*                                                                          COOCH.sub.3                                                                         0.33 (ethyl                                                                   acetate)                                       2.6 1 O methyl 3-OH(3cis)*                                                                             COOCH.sub.3                                          2.7 1 O OCH.sub.2 C.tbd.CH                                                                   3-OH(3cis)*                                                                             COOCH.sub.3                                          2.8 1 O isopropoxy                                                                           3-OH(3cis)*                                                                             COOCH.sub.3                                          2.9 2 O isopropoxy                                                                           3-oxo     COOC.sub.2 H.sub.5                                                                  0.44 (diethyl                                                                 ether)                                         2.10                                                                              1 S isopropoxy                                                                           3-OH(3cis)*                                                                             COOCH.sub.3                                          2.11                                                                              2 O isopropoxy                                                                           3-OH(3cis)*                                                                             COOH  0.1 (CH.sub.2 Cl.sub.2 -                                                      CH.sub.3 OH 9:1)                               2.12                                                                              1 O isopropoxy                                                                           3-OH(3cis)*                                                                             COOH  153-154° C.                             2.13                                                                              1 O isopropoxy                                                                           3-Cl(3cis)*                                                                             COOH  158-159° C.                             2.14                                                                              1 O OCH.sub.2 .tbd.CH                                                                    3-Cl(3cis)*                                                                             COOH  162-163° C.                             __________________________________________________________________________     *the geom. configuration is with respect to group R.sub.17.              

What is claimed is:
 1. A compound of the formula (I) ##STR5## wherein R₁is H, C₁₋₄ alkyl, C₂₋₄ alkenyl or halo;R₂ is H or halo; R₃ is OH, oxo,or halo; R₄ is H or halo; R₅ is halo, cyano or C₁₋₄ alkyl; R₆ is halo;NO₂ ; NH₂ ; CN; C₂₋₈ alkynyl; C₂₋₈ alkenyloxy; C₂₋₈ alkynyloxy; S(C₁₋₄alkylene)_(k) R₇, optionally substituted by CN; C₁₋₈ alkyl, optionallysubstituted with one or more groups selected from halo and CN; C₂₋₈alkenyl, optionally substituted by one or more halo; C₂₋₅alkoxycarbonylC₁₋₄ alkyl, whereby the carbon atom of the alkyl groupalpha to the alkoxycarbonyl group may be substituted with one or moreC₂₋₅ alkoxycarbonyl group or a cyano group; C₂₋₅ alkoxycarbonyloxy; C₂₋₅alkoxycarbonylC₁₋₄ alkoxyC₁₋₄ alkyl; C₂₋₅ alkoxycarbonylC₂₋₅ alkenyl,whereby the alkenyl group is optionally substituted by halogen; C₁₋₄alkylthioC₁₋₄ alkyl; C₁₋₄ alkylsulfonylC₁₋₄ alkyl; C₁₋₄ alkylsulfonyl;C₁₋₄ alkylsulfonyloxy; OCH(SR₈)COOR₉ ; NR₁₀ R₁₁ ; COOR₁₂ ; C(O)NR₁₃ R₁₃; C(O)R₁₄ ; R₁₅ ; CR₁₄ (OC₁₋₂ alkyl)₂ or CR₁₄ (SC₁₋₂ alkyl)₂ ; CR₁₄═NOR₁₃ ; thienylC.sub. 1-4 akoxy, wherein the thienyl is optionally halosubstituted; or C₁₋₄ alkoxyC₁₋₄ alkoxycarbonyl; or R₅ and R₆ jointogether to form a 5- or 6-membered ring, one to three of said ringatoms optionally selected from oxygen, nitrogen and sulfur and togetherwith the phenyl ring to which they are attached form a bicyclic ringoptionally being substituted with one or more groups selected from C₂₋₅alkynyl, halo, oxo, C₁₋₄ alkylene-R₁₆, C₂₋₅ alkenyl and C₁₋₈ alkyl whichis itself optionally substituted by C₂₋₅ alkoxycarbonyl, C₁₋₄ alkoxy orCN; R₇ is H; C₁₋₄ alkyl, C₂₋₅ alkenyl, C₂₋₅ alkynyl, or C₃₋₈ cycloalkyl,which hydrocarbyl is unsubstituted or substituted by one or more halo orby CN; cyclopentanonyl; phenyl optionally substituted by O-C₁₋₄alkylene-COOR₈ ; C₂₋₅ alkanoyl; C₂₋₅ alkoxycarbonyl wherein the alkoxyis optionally substituted by C₁₋₄ alkylthio; C(O)NR₈ R_(8') ;C(═NOR₈)COOR_(9') ; P(O)(OR₈)OR₈ ; R₁₅ ; C(O)R₁₅ ;cyclopentaoxycarbonyl; or phenoxy; R₈ and R_(8') independently are C₁₋₄alkyl; R₉ is C₁₋₄ alkyl optionally substituted by one or more halo; R₁₀is H or C₁₋₄ alkyl; R₁₁ is H; C₁₋₄ alkyl, optionally substituted byP(O)(OR₈)R_(8') ; C₂₋₅ alkanoyl; C₂₋₅ alkoxycarbonyl; or C₂₋₅alkoxycarbonylC₁₋₄ alkyl; R₁₂ is H; C₁₋₁₀ alkyl; phenyl; an aromatic 5-or 6-membered ring comprising 1 to 3 heteroatoms selected from oxygen,sulphur and nitrogen N═C₂₋₈ alkylidene; or C₁₋₄ alkyl substituted by oneor more groups selected from C₁₋₁₀ alkyl, cycloalkyl, C₂₋₁₀ alkenyl,cycloalkenyl, C₂₋₁₀ alkynyl, NR₁₀ R₁₁, C₁₋₄ alkylthio, CN, phenyl, anaromatic 5- or 6-membered ring comprising 1 to 3 heteroatoms selectedfrom oxygen, sulphur and nitrogen, C₂₋₅ alkanoyl, halo, C₁₋₄ alkoxy,tri(C₁₋₄ alkyl)silyloxy, tri(C₁₋₄ alkyl)silyl, C₂₋₅ alkoxycarbonyl,P(O)(OR₈)OR_(8'), C₂₋₅ alkanoyloxy, and di(C₁₋₄ alkyl)aminocarbonyloxyin which both alkyl groups may be tied together to form a saturated 5-to 6-membered heteroring one to three of the heteroatoms optionallyselected from O, S and N, and any N-heteroatom optionally substitutedwith a hydrogen or a C₁₋₄ alkyl group; R₁₃ is H or C₁₋₄ alkyl; andR_(13') is H, C₁₋₄ alkyl, C₁₋₄ alkoxy, phenyl, CHO, C₂₋₅ -alkanoyl, C₁₋₄alkylsulfonyl, C₂₋₅ alkoxycarbonylC₁₋₄ alkyl or C₂₋₅ akoxycarbonylC₁₋₄alkoxy; or R₁₃ and R_(13') together form a 5- to 6-membered heteroringoptionally containing one or two heteroatoms selected from O, S and N,and any N-heteratom optionally substituted by C₁₋₄ alkyl; R₁₄ is H orC₁₋₄ alkyl; R₁₅ is a heterocyclic ring having 5 or 6 ring atoms, one tothree of said ring atom being selected from oxygen, sulfur and nitrogen,which ring is optionally substituted with one or more groups selectedfrom C₁₋₄ alkyl and C₂₋₅ alkoxycarbonyl; R₁₆ is tetrahydropyranyl,5,6-dihydro-2H-thiinyl, pyridyl, pyrazinyl, oxazolyl, or oxadiazolyl allof which are optionally substituted with C₁₋₄ alkyl; X₁ and X₂ areindependently O or S; k is 0 or 1; and n and m are independently 1 or 2.2. The compound of formula (I) ##STR6## wherein X₁ and X₂ are oxo;R₁ isH or halo; R₂ is H; R₃ is OH, halo, or oxo; R₄ is F; R₅ is halo, cyanoor C₁₋₄ alkyl; R₆ is C₁₋₄ alkoxy, C₂₋₅ alkynyl, C₂₋₅ alkoxycarbonyloxy,C₂₋₅ alkoxycarbonyl, C₂₋₅ alkoxycarbonylC₁₋₄ alkoxy, phenoxyC₁₋₄ alkoxy,C₁₋₄ alkoxyC₁₋₄ alkoxycarbonyl, C₂₋₅ alkoxycarbonylC₁₋₄ alkyl; wherebythe carbon atom of the alkyl group alpha to the alkoxycarbonyl group maybe substituted with one or more C₂₋₅ alkoxycarbonyl group or a cyanogroup, or C₂₋₅ alkoxycarbonylC₂₋₅ alkenyl; whereby the alkenyl group isoptionally substituted by halogen; and n and m are independently 1 or 2.3. The compound of formula (I) according to claim 2 wherein R₃ is F, R₅is Cl and m is
 1. 4. The compound of formula (I) according to claim 2wherein R₁ is H; R₃ is halo; R₆ is C₁₋₄ alkoxy; and n is
 2. 5. Thecompound of formula (I) according to claim 1 wherein R₃ is F, R₅ is Cland m is
 1. 6. The compound of formula (I) according to claim 2 whereinR₃ is 7-F and R₆ is isopropyl.
 7. The compound of formula (I) accordingto claim 1 whereinR₁ is H or halo; R₂ is H; R₃ is OH, halo, or oxo; R₄is F; R₅ is Cl, CN, Br or C₁₋₄ alkyl; X₁ and X₂ are oxo; n is 1 or 2 andR₆ is halo; NO₂ ; CN; C₂₋₈ alkynyl; C₂₋₈ alkenyloxy; C₂₋₈ alkynyloxy;S(C₁₋₄ alkylene)_(k) R₇, optionally substituted by CN; C₁₋₈ alkyl,optionally substituted with one or more groups selected from halo andCN; C₂₋₈ alkenyl, optionally substituted by one or more halo; C₂₋₅alkoxycarbonylC₁₋₄ alkyl, whereby the carbon atoms of the alkyl groupalpha to the alkoxycarbonyl group may be substituted with one or moreC₂₋₅ alkoxycarbonyl group or a cyano group; C₂₋₅ alkoxycarbonyloxy; C₂₋₅alkoxycarbonylC₁₋₄ alkoxyC₁₋₄ alkyl; C₂₋₅ alkoxycarbonylC₂₋₅ alkenyl,whereby the alkenyl group is optionally substituted by halogen; C₁₋₄alkylthioC₁₋₄ alkyl; C₁₋₄ alkylsulfonylC₁₋₄ alkyl; C₁₋₄ alkylsulfonyl;C₁₋₄ alkylsulfonyloxy; OCH(SR₈) COOR₉ ; NR₁₀ R₁₁ ; COOR₁₂ ; C(O)NR₁₃R_(13') ; C(O)R₁₄ ; R₁₅ ; CR₁₋₄ (OC₁₋₂ alkyl)₂ l or CR₁₄ (SC₁₋₂ alkyl)₂; CR₁₄ ═NOR₁₃ ; thienylC.sub. 1-4 alkoxy wherein the thienyl isoptionally halo substituted; or C₁₋₄ alkoxyC₁₋₄ alkoxycarbonyl.
 8. Thecompound of formula (I) according to claim 7 wherein R₁ is H, R₅ is Cl,and R₆ is C₁₋₄ alkoxy, C₂₋₅ alkynyloxy, C₂₋₅ haloalkenyl, C₂₋₅ alkynyland COOR₁₂.
 9. The compound of formula (I) according to claim 7 whereinR₁ is H; R₃ is F; R₅ is Cl; and m is
 1. 10. The compound of formula (I)according to claim 7 whereinn is
 1. 11. A herbicidal compositioncomprising a herbicidally effective amount of a compound as defined inclaim 1 and an agriculturally acceptable carrier.
 12. A herbicidalcomposition comprising a herbicidally effective amount of a compound asdefined in claim 7 and an agriculturally acceptable carrier.
 13. Aherbicidal composition comprising a herbicidally effective amount of acompound as defined in claim 2 and an agriculturally acceptable carrier.14. A method of combatting weeds which comprises applying to the weedsor their locus a herbicidally effective amount of a compound as definedin claim
 2. 15. A compound of Formula (I): ##STR7## wherein R₁ is H,C₁₋₄ alkyl, C₂₋₄ alkenyl or halo; R₂ is H or halo;R₃ is OH, oxo, C₂₋₅alkanoyloxy, C₁₋₄ alkylsulfonyloxy, C₂₋₄ alkylenedioxy or halo; R₄ is Hor halo; R₅ and R₆ together with the phenyl ring to which they areattached form an optionally substituted indanone, benzazinone,benzoazinone, benzoxazinone, benzothiazinone, benzodioxane, benzopyrene,benzopyrone, benzazole, benoxzolone, benzothiazolone, benzofurane, orbenzodioxolane wherein said substituents are independently selected fromthe group C₂₋₈ alkynyl, halo, oxo, C₁₋₄ alkylene- R₁₆, C₂₋₈ alkenyl andC₁₋₈ alkyl which is itself optionally substituted by C₂₋₅alkoxycarbonyl, C₁₋₄ alkoxy or CN; R₁₆ is tetrahydropyranyl,5,6-dihydro- 2H-thiinyl, pyridyl, pyrazinyl, oxazolyl or oxadiazolyl allof which are optionally substituted with C₁₋₄ alkyl; X₁ and X₂ areindependently O or S; k is 0 or 1, and m and n are independently 1 or 2.16. A herbicidal composition comprising a herbicidally effective amountof a compound as defined in claim 15 and an agriculturally acceptablecarrier.